TY - JOUR

T1 - The role of nanoparticulate agglomerates in TiO2 photocatalysis

T2 - degradation of oxalic acid

AU - Ivanova, Irina

AU - Mendive, Cecilia B.

AU - Bahnemann, Detlef

PY - 2016/6/1

Y1 - 2016/6/1

N2 - Abstract: The simultaneous bimodal study of the photocatalytic oxalic acid degradation by aqueous TiO2 suspensions revealed that particular systems possess the capacity to protect a certain amount of oxalic acid from oxidation, thus hindering, to some extent, the photocatalytic reaction. While measurements of the oxalic acid concentration in the bulk liquid phase indicated full photocatalytic degradation; in situ pH-stat measurements allowed the quantification of the amount of oxalic acid remaining in the part of the nanoparticulate agglomerates where light could apparently not access. An explanation for this phenomenon takes into account the possibility of the formation of TiO2 agglomerates in which these molecules are hidden from the effect of the light, thus being protected from photocatalytic degradation. Studies of different TiO2 materials with different particle sizes allowed a deeper exploration of this phenomenon. In addition, because this property of encapsulating pollutant molecules by photocatalytic systems is found to be a reversible phenomenon, P25 appears to be more convenient and advantageous as compared to the use of large surface area photocatalysts. Graphical Abstract: Fig.: Deaggregation of TiO2 particle agglomerates upon UV illumination. [Figure not available: see fulltext.]

AB - Abstract: The simultaneous bimodal study of the photocatalytic oxalic acid degradation by aqueous TiO2 suspensions revealed that particular systems possess the capacity to protect a certain amount of oxalic acid from oxidation, thus hindering, to some extent, the photocatalytic reaction. While measurements of the oxalic acid concentration in the bulk liquid phase indicated full photocatalytic degradation; in situ pH-stat measurements allowed the quantification of the amount of oxalic acid remaining in the part of the nanoparticulate agglomerates where light could apparently not access. An explanation for this phenomenon takes into account the possibility of the formation of TiO2 agglomerates in which these molecules are hidden from the effect of the light, thus being protected from photocatalytic degradation. Studies of different TiO2 materials with different particle sizes allowed a deeper exploration of this phenomenon. In addition, because this property of encapsulating pollutant molecules by photocatalytic systems is found to be a reversible phenomenon, P25 appears to be more convenient and advantageous as compared to the use of large surface area photocatalysts. Graphical Abstract: Fig.: Deaggregation of TiO2 particle agglomerates upon UV illumination. [Figure not available: see fulltext.]

KW - Deaggregation

KW - Oxalic acid

KW - Photocatalysis

KW - Semiconductor nanoparticles

KW - TiO

UR - http://www.scopus.com/inward/record.url?scp=84978066673&partnerID=8YFLogxK

U2 - 10.1007/s11051-016-3495-x

DO - 10.1007/s11051-016-3495-x

M3 - Article

AN - SCOPUS:84978066673

VL - 18

JO - Journal of Nanoparticle Research

JF - Journal of Nanoparticle Research

SN - 1388-0764

IS - 7

M1 - 187

ER -